How to Add Refrigerant to a Car Air Conditioner?
2 Answers
There are two methods for adding refrigerant to a car air conditioner: the high-pressure side charging method and the low-pressure side charging method. Here are the relevant details: 1. Applicable situations: There are two scenarios when a car air conditioner needs refrigerant: First, if the air outlet temperature cannot reach below 16 degrees Celsius, refrigerant needs to be added. Second, if the air outlet temperature can reach below 16 degrees Celsius but takes a long time (e.g., more than 5-6 minutes), refrigerant also needs to be added. 2. Two methods: There are two methods for adding refrigerant to a car air conditioner. One is the high-pressure side charging method, which is suitable for charging after leak detection and vacuuming. Note that this method requires the compressor to be turned off, the engine to be stopped, and the refrigerant tank to be inverted. The other is the low-pressure side charging method, which involves charging gas and is characterized by slow charging speed. It is typically used for supplementing refrigerant.
Just helped my neighbor recharge the refrigerant in their old Camry yesterday. This job must follow the steps carefully. First, check the A/C system for leaks by spraying UV dye at pipe connections – green glow indicates a leak. After confirming the system is sealed, connect the blue low-pressure hose to the car's A/C low-pressure port (usually on the left-side metal pipe under the hood) and the red high-pressure hose to the refrigerant can. Then, start the engine, turn the A/C to max cooling and recirculation mode. Once the compressor engages, begin slowly adding refrigerant. Keep a close eye on the pressure gauge – in summer, low pressure should stay between 25-40 psi. Adding too fast can damage the compressor. Finally, use an infrared thermometer to check vent temperature; it should be below 8°C to meet standards. For safety, it's best to have a professional shop handle this – refrigerant cans have pressure valves and improper handling can cause frostbite.
